Logical request, but.....
It would be cool to be able to get a graph like that, but as far as I know all you can get are numbers in a chart.
I find the streamflow site very useful, but you really have to play with it, and learn how to use it. It is not really a user friendly site. There is a lot of capability there, one of the reasons that it is not user friendly. For example, you can get day by day flow for any year or series of years. I have spent a lot of time playing with the site, looking at the data different ways.
I am an engineer, so wading through piles of numbers is a normal activity for me. I agree that a graph is easier and faster to read. The info you need is there, but you have to work to get it, and then work again to analyze it. I guess I see the glass half full, not half empty, and focus on the available information.
If there are cool graphical tools, I would love to know about it. Maybe somebody has a script that takes tabular data, (or tab-limited data), manipulates it, and puts out a graph. I am not that much of a computer jock, so to write that script is probably beyond my skill set.
Perhaps the coolest graph would be something that would plot daily flow for multiple selected years on the same chart, so you could visually compare different years and different months. Maybe add the ability to include some smoothing of the charts.
Let's see what folks have to say.